Common Dodder, Cuscuta gronovii
Convolvulaceae or Morning Glory Family
(some books place the genus Cuscuta in its own family, the Cuscutaceae or Dodder Family)

Plant

A very peculiar plant, lacking both leaves and roots. Stem is a twining vine, colored orange, sprawling over and winding around other plants. Flowers in dense clusters, small, bell-shaped, with 5 greenish sepals, 5 white petals, a fat, berry-like carpel, and 5 orange stamens. The carpel (female organ) develops into whitish berry-like fruits (middle row right) that mature into dry capsules containing hard, dark seeds. Blooms in late summer with fruits maturing in late autumn.

Dodder is a parasitic plant, lacking chlorophyll and unable to carry out photosynthesis; it literally sucks sap out of other plants like vegetable vampires. The seeds sprout in the soil like a normal plant. The seedling grows quickly, reaching out in a desperate effort to contact another plant before the food stored in the seed runs out and the seedling dies of starvation. If a victim is contacted the dodder wraps tightly around its stem.

Tiny, pad-like organs called haustoria (middle row, left) develop and grow down into the victim's stem to suck sap. Meanwhile the lower part of the dodder, rooted in the ground, withers away. Once dodder has its haustoria in a victim it obtains all food and water from the hapless host.

A peculiar and creepy native of most of North America, absent only from a few western states, British Columbia, and the northern Canadian territories. Likes open, moist areas; in the Park it has been found along the bikeway near the South Bridge.

Eight other species of dodder occur in Virginia, some native and some introduced from Europe. Many specialize on particular species of host. Common dodder is the most common, and is happy to attack a wide range of victims. The plants in the picture are sucking sap from goldenrods and hog peanut.

Flowers
Haustoria Inflorescence Young fruits
Infructescence Fruits Seeds

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